#include <bits/stdc++.h>
using namespace std;

int main() {
  int a, b;
  cin>>a>>b;
  string s;
  cin>>s;
  double t = 0;
  int i = 4;
  while (i < s.length()) {
    if (s[i] == '.') {
      t += 0.1 * (s[i+1] - '0');
      break;
    }
    t = 10 * t + s[i] - '0';
    ++i;
  }
  if (s[3] == '-') {
    t *= -1;
  }
  int d = (int)((t - 9) * 60 + 60 * 24) % (60 * 24);
  int x = (a + d / 60) % 24;
  int y = b + d % 60;
  if (y >= 60) {
    ++x;
    y %= 60;
  }
  if (x == 24) {
    x = 0;
  }
  printf("%02d:%02d\n", x, y);

}